Process of producing azo dyestuffs



a 1 I v 1 I date 01x1 ln'ventloni the Palts g V 1. As new products, monoazo dyestuffs ob- ?ate'nted Nev. 6, 192? I I H i y UNITED STATES imi times.

KARL HEUSNER AND MAX snvion, 0F nnvnmzusnn, NEAR eoLoGnEbunting-nine, GERMANY, ASSIGNORS TO GBAS'SELLI DYESTUFF. CORPOBATEQN, 0 NE YORK, N. Y.', A CORPORATION on DELAWARE. i

PROCESS OF ERODUCING AZO D YES TUF-FSJ No Drawing I Application filed. June 7, 1927, SerialNo. 197,220, in Germany. Apriic; 1 825.

This application is a continuation in part 2. 17 .3 parts by weight'of in-sulfanilic acid of our application Ser. No. 97,759, filed March are diazotizedand coupled with 341.7 parts by 26, 1926, and relates to the preparation of weight of Z-naphthyl-sulfaniinic;6-sulfonic aZo dyestuffs by coupling B-naphthyl-sulacid sodium salt in an aqueous reaction'rnix- -5' fainiiiic acid'and its derivatives such as the ture containing 28 parts by weight of sodium chloro, allryl and sulfonic acid derivatives carbonate at t) G. Afterseyeralhours when with m compounds the coupl ng is complete the dyestuif withthe B th use f th fi mi i id th sulfaminlc group intact may be salted out of ti proceeds ll very uniformly prothe yellowishorange solution and dried, giv- 10 ducing the dyestuffs with excellent yields and g a y wis OITLHP'Q PQ Th9 dyeeliminating the formation of undesirable bystuff dyes wool a yellowish orange'color. or decomposition products. This is particu- The sulfo group of the sulfaminic group may larly valuable if it is desired to obtain the be split off by heating w th dilute hydrodi d t ff ith the free amino chloric acid. The dyestuff has probablythe 15 group, as we have further found that the formula:

sulfo group of the sulfaminic acid ca rbe 1 V BH easily eliminated, as for instance, by bo1l1ng the sulfaminic azo compounds in aqueous so- SOsH 8 5 lution with dilute mineral acids. By this *2 20 procedure better yields and more uniform 1 4 products are obtained than when coupling U directly the free amino compound with the H respective diazo compound. N

The following examples will further illus- *W hu weight: tained by coupling diazo compounds with a 1. 17.3 parts by weight of p-sulfanilic acid B hth 1- 1f ninic acid compound, being, are diazotized and coupled with 24.5 parts by h d i d d l i d g ll ddi h weight of B-naphthyl-sulfaininic acid sodium to yellowish-orange powders, dyeing wool in 30 salt in an ice cold aqueous solution thereof orange to yellowish-orange shades.

containing 28 parts by weight of sodium & V 2. As a new product, the monoazo dyestuff bonate. The reaction mixture is stirred for having in its free state most probably the several hours until the coupling is complete. f l I The resulting dyestuff with the sulfaminic r 35 group intact can be isolated in the well known way by salting out and dried without decomposition. The dyestuif in dry powdered Hoisform has brick-red color and dyes wool an orange color. The sulfo group may be split H 40 off by heating with dilute hydrochloric acid. v p

The dyestuif in its free state has probably-the 3 formula:

said dyestuff, in dry powdered form, being a brick-red powder dyeing wool an orange color. 45 HO s ON N /1 t In testimony whereof, we affix our signa- 3 ures. I

L 11 I KARL HEUSNER.

soan v MAX SIMON. 

